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| HAL : hal-00468432, version 4 |
| arXiv : 1004.0067 |
| Fiche détaillée |  Récupérer au format |
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| Versions disponibles : | v1 (01-04-2010) | v2 (08-09-2010) | v3 (09-09-2011) | v4 (27-01-2012) |
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| Fast algorithmic Nielsen-Thurston classification of four-strand braids |
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| Matthieu Calvez 1Bert Wiest 1 |
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| (30/03/2010) |
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| We give an algorithm which decides the Nielsen-Thurston type of a given four-strand braid. The complexity of our algorithm is quadratic with respect to word length. The proof of its validity is based on a result which states that for a reducible 4-braid which is as short as possible within its conjugacy class (short in the sense of Garside), reducing curves surrounding three punctures must be round or almost round. |
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| 1 : | Institut de Recherche Mathématique de Rennes (IRMAR) |
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CNRS : UMR6625 – Université de Rennes 1 – École normale supérieure de Cachan - ENS Cachan – INSA Rennes – Université Rennes II |
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| Géométrie analytique |
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| Domaine | : | Mathématiques/Théorie des groupes |
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| braids – Nielsen-Thurston classification – algorithm – Garside theory |
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| Liste des fichiers attachés à ce document : | ||||||||||
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| hal-00468432, version 4 | |
| http://hal.archives-ouvertes.fr/hal-00468432 | |
| oai:hal.archives-ouvertes.fr:hal-00468432 | |
| Contributeur : Bert Wiest | |
| Soumis le : Vendredi 27 Janvier 2012, 11:02:40 | |
| Dernière modification le : Lundi 30 Janvier 2012, 17:07:57 | |
